Abstract:The ability to rapidly detect DNA nanoparticulate biomarkers and drug delivery nanoparticles directly in blood is a major challenge for early disease detection and nanomedicine. We now show that a microarray dielectrophoretic (DEP) device can be used to rapidly isolate and detect high molecular weight (hmw) DNA nanoparticulates and nanoparticles directly from whole blood. At DEP frequencies of 5kHz-10kHz both fluorescent-stained hmw-DNA and 40nm fluorescent nanoparticles separate from the blood and become highly concentrated at specific DEP high field regions over the microelectrodes, while blood cells move to the DEP low field regions. The blood cells can then be removed by a simple fluidic wash while the hmw-DNA and nanoparticles remain highly concentrated. The hmw-DNA could be detected at a level of <260ng/ml, and the nanoparticles at <9.5 x 109 particles/ml, detection levels that are well within the range for viable clinical diagnostics and drug nanoparticle monitoring. Hmw-DNA could also be detected directly in blood from patients with Chronic Lymphocytic Leukemia (CLL)